Engineered aluminum alloy and method of fabricating the same

ABSTRACT

Provided are an aluminum alloy having an adjusted microstructure in an aluminum matrix or an aluminum alloy matrix for high elongation percentage or high strength and a method of fabricating the same. The aluminum alloy includes an aluminum-based matrix; and a nonmetal element solidified in the aluminum-based matrix, wherein stacking fault energy of the aluminum alloy is decreased compared to that of pure aluminum.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Korean Patent Application No.10-2016-0021495, filed on Feb. 23, 2016 and priority of Korean PatentApplication No. 10-2016-0183446, filed on Dec. 30, 2016, in the KIPO(Korean Intellectual Property Office), the disclosure of which isincorporated herein entirely by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a metal material, and moreparticularly, to aluminum that is adjusted to have high elongation orhigh strength and a method for fabricating the same.

Description of the Related Art

Generally, aluminum or its alloy is a material having a wide range ofindustrial applications because it may be fabricated in various shapesdue to lightweight and durable characteristics of aluminum. Aluminumitself is easily deformed due to its low strength, but an aluminum alloyhas high strength and high reliability due to elements added thereto tothe extent that it may be applied to the automobile or aircraftindustry. Recently, due to their excellent mechanical strengths andlightweights, aluminum alloys have been applied to various fields, suchas automobiles and aircraft, as well as various other fields, such asarchitecture, chemistry, robots, and electronic products.

Recently, high-strength aluminum and method of fabricating the same arebeing actively researched for development of components used in thefields of automobiles, bicycles, electric or electronics, or robots.Generally, as the number of kinds of elements added to an aluminummatrix increases, improvements of strength and corrosion resistance maybe expected, but elongation percentage for improving the workability ofaluminum-based material is not improved or is rather reduced.

Furthermore, in order to improve the strength of pure aluminum having alow strength, it is generally preferable to form an aluminum alloy withan element, such as silicon (Si), magnesium (Mg), copper (Cu), manganese(Mn) and strengthen solid solution of the corresponding element in analuminum-based matrix or strengthen precipitation of compound or secondphase precipitation, thereby improving strength of the aluminum alloy.The aluminum alloy may be classified into a non-heat-treated alloy and aheat-treated alloy depending on whether it is hardened via a heattreatment. The above-stated non-heat-treated alloy is improved instrength by strengthening by a second phase or a compound based on anelement, such as silicon, magnesium, or manganese, as described above.Examples of the non-heat-treated alloys include Al—Si alloys, Al—Mgalloys, and Al—Mn alloys.

The strength of the heat-treated alloy may be determined depending onthe kind of alloying elements. For example, in an aluminum alloy towhich copper (Cu) or zinc (Zn) is added, solid solubility of the addedelement increases as the temperature rises, and may be hardened byformation of precipitates via an aging treatment. The heat-treatedalloys include Al—Cu alloys, Al—Zn alloys, and Al—Mg—Si alloys. However,in the case of the above-stated heat-treated alloy, since it isnecessary to take main composition or brittleness into account, alloyingelements to be added are limited. An aluminum alloys, which isstrengthened by formation of a precipitate (a metal compound) by addinga heterogeneous metal to aluminum may be expected to exhibit improvedstrength as compared to conventional heat-treated alloys.

SUMMARY OF THE INVENTION

Provided is a highly-stretchable aluminum alloy exhibiting excellentmechanical properties such as strength and improved elongationpercentage that provides improved workability, the aluminum alloy thatmay be obtained at a high yield.

Provided is a method of fabricating the highly-stretchable aluminumalloy.

Provided is an aluminum alloy capable of improving the strength of thealuminum alloy by forming a new reaction compound in the aluminum alloythrough heat treatment to provide an efficient strengthening mechanismof the aluminum alloy.

Provided is a method of easily fabricating an aluminum alloy having theabove advantages.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

According to an aspect of an embodiment, an aluminum alloy includes analuminum-based matrix; and a nonmetal element solidified in thealuminum-based matrix, wherein stacking fault energy of the aluminumalloy is decreased compared to that of pure aluminum. The nonmetalelement may include at least one of oxygen and nitrogen.

The nonmetal element may be solidified to less than or equal to 1 wt %of aluminum of the aluminum-based matrix. In this case, the stackingfault energy of the aluminum alloy may be less than 100 mJ/m².

In the aluminum alloy, at least a portion of the aluminum-based matrixmay include a twin boundary or a partial dislocation. The nonmetalelement may be solidified in the aluminum alloy by adding nanoparticlesof a metal compound between the nonmetal element and a heterogeneousmetal element to molten aluminum and decomposing the nanoparticles intothe nonmetal element and the heterogeneous metal element.

According to an embodiment, the aluminum alloy may be hardened via acooling operation. Furthermore, the aluminum alloy may be aged withoutbeing cooled.

According to an aspect of another embodiment, a method of fabricating analuminum alloy, the method includes providing the melt of aluminum or analuminum alloy providing an aluminum-based matrix; adding nanoparticlesof a metal compound between a nonmetal element and a heterogeneous metalelement to the melt; uniformly dispersing the nonmetal element and theheterogeneous metal element in the melt through decomposition of thenanoparticles into the nonmetal element and the heterogeneous metalelement; and cooling the melt so as to solidify the nonmetal element inat least a portion of the aluminum-based matrix.

The stacking fault energy of the aluminum alloy may be less than 100mJ/m². The nonmetal element may include at least one of oxygen andnitrogen. Furthermore, the nonmetal element may be solidified to lessthan or equal to 1 wt % of aluminum of the aluminum-based matrix. Theheterogeneous metal element may include copper, iron, zinc, titanium,magnesium, or a mixture of two or more thereof.

The average size of the nanoparticles may be from about 20 nm to about100 nm. According to some embodiments, the aluminum alloy in which thenonmetal element is solidified may be hardened via a cooling operation.According to another embodiment, the aluminum alloy in which thenonmetal element is solidified may be artificially aged without beingcooled.

According to an aspect of another embodiment, an aluminum alloy includesan aluminum-based matrix; and a precipitation compound dispersed in thealuminum-based matrix, wherein the precipitation compound includes acompound containing aluminum, one or more transition metals, and one ormore nonmetal elements or a compound containing the above-statedelements.

According to an embodiment, the average size of the precipitationcompound may be from about 10 nm to about 1 μm. The transition metal mayinclude at least one of chromium (Cr), iron (Fe), and manganese (Mn).

Furthermore, the nonmetal element may be supersaturated in the aluminumalloy and includes at least one of oxygen, nitrogen, and carbon. Theprecipitation compound may be formed via a heat treatment.

The aluminum-based matrix may include an aluminum alloy, and alloyingelements of the aluminum alloy may include at least one of silicon (Si),zinc (Zn), magnesium (Mg), and copper (Cu). In addition, in anembodiment, the aluminum alloy may be work hardened by plasticity.

According to an aspect of another embodiment, a method of fabricating analuminum alloy, the method includes providing the melt of an aluminumalloy including aluminum and a first transition metal; adding a nonmetalelement-containing precursor including at least one of a first reactioncompound between the first transition metal and a nonmetal element, asecond reaction compound between a second transition metal differentfrom the first transition metal and the nonmetal element, and a thirdreaction compound between a non-transition metal and the nonmetalelement to the melt; supersaturating the nonmetal element in the meltthrough decomposition of the nonmetal element-containing precursor inthe melt; forming a casted material by hardening the melt; and forming aprecipitation compound between aluminum, a transition metal, and anonmetal element dispersed in an aluminum-based matrix by heat-treatingthe hardened casted material.

Furthermore, the first transition metal may include at least one ofchromium (Cr), iron (Fe), and manganese (Mn). The nonmetal element mayinclude at least one of oxygen, nitrogen, and carbon.

According to an embodiment, the non-transition metal of the thirdreaction compound may include at least one of aluminum (Al), silicon(Si), magnesium (Mg), and tungsten (W). The nonmetal element-containingprecursor may be added to the melt in the form of power having theaverage diameter within a range from about 5 nm to about 50 nm.

The nonmetal element-containing precursor may be added in the range from0.01 wt % to 5.0 wt % of the total weight of the melt. Furthermore, themethod may further include plastic working and hardening the hardenedcasted material before the hardened casted material is heat treated. Theheat treatment may be performed at a temperature within a range from120° C. to 600° C.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages will become more apparent tothose of ordinary skill in the art by describing in detail exemplaryembodiments with reference to the attached drawings, in which:

FIGS. 1A and 1B are transmission electron microscope (TEM) analysisimages showing the microstructure of an aluminum alloy according to anembodiment of the present invention;

FIG. 2 is a graph showing a result of X-ray diffraction analysis formeasuring stacking fault energy (SFE) of an aluminum alloy having a twinboundary or partial dislocation according to an embodiment of thepresent invention;

FIGS. 3A through 3C are stress-deformation graphs showing results ofmeasurement of elongation percentages of aluminum alloys havingdifferent compositions according to an embodiment of the presentinvention;

FIG. 4 is a flowchart of a method of fabricating an aluminum alloyaccording to an embodiment of the present invention;

FIGS. 5A and 5B are transmission electron microscope images showingprecipitation compounds in an aluminum-based matrix by heat treatmentaccording to an embodiment of the present invention, and FIG. 5C is agraph showing ingredients of the precipitation compounds analyzed via anenergy dispersive X-ray spectroscopy (EDS);

FIG. 6 is a scanning electron microscope image showing a cross-sectionalmicrostructure of an aluminum alloy casted material supersaturated witha nonmetal element before heat treatment, according to a comparativeembodiment;

FIG. 7 is a graph showing results of measuring tensile strength of analuminum alloy according to an embodiment of the present invention andtensile strength of an aluminum alloy according to a comparativeembodiment;

FIGS. 8A and 8B are graphs showing increases tensile strength andstrength of aluminum alloys according to various compositions of aprecipitation compound according to an embodiment of the presentinvention, respectively;

FIG. 9 is a graph showing results of measuring tensile strength of analuminum alloy including a precipitation compound according to anotherembodiment and an aluminum alloy according to a comparative embodiment;and

FIG. 10 is a graph showing results of measuring tensile strength of analuminum alloy (solid line curve) including a precipitation compoundaccording to another embodiment and an aluminum alloy according to acomparative embodiment.

In the following description, the same or similar elements are labeledwith the same or similar reference numbers.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “includes”,“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof. In addition, a term such asa “unit”, a “module”, a “block” or like, when used in the specification,represents a unit that processes at least one function or operation, andthe unit or the like may be implemented by hardware or software or acombination of hardware and software.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Preferred embodiments will now be described more fully hereinafter withreference to the accompanying drawings. However, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the disclosure to those skilled in the art.

An aluminum alloy according to an embodiment of the present inventionhas a structure in which a nonmetal element is solidified in analuminum-based matrix. The aluminum-based matrix refers to a matrixformed of pure aluminum or an aluminum alloy. In the aluminum alloy, aresult of X-ray diffraction analysis in which no peak related to acompound due to a reaction between aluminum and the nonmetal element isshown other than a peak related to the crystalline phase of aluminumsupports that, in the aluminum alloy, the nonmetal element is a solidsolution solidified in the aluminum-based matrix. The fact has beenconfirmed through X-ray diffraction analysis (XRD) and X-rayphotoelectron spectroscopy (XPS) over a wide area of a fabricatedaluminum-based matrix and, as shown in the XRD result of FIG. 2 (referto the curve As-cast), only a pure aluminum crystal structure wasdetected.

The nonmetal element may include at least one of oxygen and nitrogen.The nonmetal element may be solidified to an amount of 1 wt % or less ofthe amount of aluminum. When the amount of the nonmetal element exceeds1 wt % of aluminum, oxidation of the aluminum alloy occurs at a highpriority, and thus it becomes difficult to harden the aluminum alloy. Asa result, the elongation percentage of the aluminum alloy decreases.

The aluminum alloy may include a heterogeneous metal element other thanaluminum. The heterogeneous metal element may include at least one ofcopper, iron, zinc, titanium, and magnesium. The heterogeneous metalelement may be solidified to a range of 4 wt % or less, and theheterogeneous metal element may be solidified in an aluminum-basedmatrix in a substitutional or interstitial manner, but the presentinvention is not limited thereto. According to an embodiment,considering the atomic size and crystal structure of aluminum, theheterogeneous metal element, and a nonmetal heterogeneous element, theheterogeneous metal element may be mainly solidified in a substitutionalmanner and the heterogeneous nonmetal element may be mainly solidifiedin an interstitial manner.

An aluminum alloy as a solid solution according to an embodiment of thepresent invention may be fabricated using a casting process. Accordingto an embodiment, the fabrication of the aluminum alloy may be initiatedby providing melt. For example, the melt may be provided by heating purealuminum by using an electric melting furnace.

In order to provide a nonmetal element that is solidified in thealuminum-based matrix, oxide particles or nitride particles of theheterogeneous metal element may be added to the melt. The oxideparticles or nitride particles may have an average size (or diameter)from about 20 nm to about 100 nm. When the average size of the particlesexceeds 100 nm, the oxide particles or nitride particles of theheterogeneous metal element may not be decomposed or may not bedispersed evenly in the aluminum matrix, and thus it becomes easier toform the second phase and it becomes difficult to form a solid solutionof a nonmetal element. When the average size of the particles is lessthan 20 nm, it becomes difficult for the particles to be uniformlydispersed in the aluminum matrix due to the attractive force between theparticles, and thus the second phase may be formed or solidification maybecome difficult.

The heterogeneous metal element may be copper, iron, zinc, titanium,magnesium or a mixture of two or more thereof, and the oxide particlesor nitride particles may be, for example, copper oxide powder, ironoxide powder, zinc oxide powder, titanium oxide powder, magnesium oxidepowder, copper nitrate powder, iron nitride powder, zinc nitride powder,titanium nitride powder, magnesium nitride powder, or a mixture of twoor more thereof. The powder selected from among the above-stated powdersmay be added to the melt within a range of 1 wt % or less of aluminum,which is the solidifying rate of the nonmetal element. A stirringprocess for uniform mixing of the powder added into the melt may beperformed.

The melt may be maintained at a temperature at which the added oxideparticles or nitride particles may be decomposed. For example, whilemaintaining the melt at a temperature in the range of 500° C. to 1,000°C., the melt may be stirred with the added particles, such that theadded particles may be homogeneously decomposed. In this process, theparticles are decomposed into the heterogeneous metal element and thenonmetal element and are uniformly dispersed in the melt, and thus theheterogeneous metal element and the nonmetal element may be solidifiedin the aluminum-based matrix. According to an embodiment, at this stage,the heterogeneous metal element and the nonmetal element may becompletely solidified. Alternatively, according to another embodiment,the nonmetal element may be completely solidified in a subsequentadditional heat treatment process.

The heterogeneous metal element and the heterogeneous nonmetal elementare uniformly dispersed in the melt and then cooled to form an aluminumcasted material. According to another embodiment, an operation forartificially aging a casted material at a high temperature may befurther performed to form the aluminum casted material. The artificialaging treatment may increase the strength of an aluminum alloy.

According to another embodiment, the aluminum casted material may besubjected to a plastic deformation process to form a processed aluminummaterial. The plastic deformation process may be a cold process and,through the plastic deformation process, work hardening of the aluminumcasted material may occur. The plastic deformation process may beperformed by rolling or pressing the aluminum casted material. However,the processes are merely examples, and the present invention is notlimited thereto. Any process capable of providing appropriatecompression or shearing stress that causes deformation may be performed.A twin boundary or partial dislocation described below may be inducedthrough the plastic deformation process.

According to another embodiment, a heat treatment may be performed onthe aluminum casted material or on the processed aluminum material. Theheat treatment may be carried out at temperatures within differentranges according to purposes. In unlimited examples, a heat treatmentfor solidification may be performed at a temperature from about 400° C.to about 500° C., a heat treatment for artificial aging may be performedat a temperature from about 120° C. to about 180° C. for a period oftime from about 6 hours to about 24 hours. A heat-treated aluminummaterial may maintain all of the microstructure, the strength, and theelongation as described above even after the heat treatment(s).

The inventors of the present invention conducted structural analysis andevaluation of elongation for the aluminum casted material, the processedaluminum material, or heat-treated aluminum material fabricated asdescribed above. As a result, the presence of twin boundaries andpartial dislocations were confirmed in all of the aluminum castedmaterial, the processed aluminum material, and heat-treated aluminummaterial, and remarkable characteristics including significant decreaseof the stacking fault energy of an aluminum alloy due to thesolidification of oxygen or nitrogen and the improved elongationpercentage due to the same were obtained.

FIGS. 1A and 1B are transmission electron microscope (TEM) analysisimages showing the microstructure of an aluminum alloy according to anembodiment of the present invention.

Referring to FIGS. 1A and 1B, the aluminum alloy is an aluminum castedmaterial in which zinc is solidified as a metal heterogeneous elementand oxygen is solidified as a nonmetal element. As described above, zincand oxygen were solidified in the aluminum-based matrix to an amount ofabout 0.5 wt % each, which is less than or equal to 1 wt % of thealuminum. Zinc oxide powder was added to the molten aluminum to solidifythe oxygen, and the zinc powder was decomposed and kneaded in the moltenaluminum.

It is confirmed that the aluminum alloy has a twin boundary (indicatedby a yellow arrow in FIG. 1A) whose lattices on both sides aresymmetrical or a partial dislocation (indicated by a yellow arrow inFIG. 1B). The twin boundary is a structure in which atoms on a firstside and atoms on a second side are symmetrically arranged around aninterface between crystal grains of the both sides as if the atoms arereflected in a mirror. The twin boundary may be formed through theabove-stated mechanical plastic deformation or the aging treatment afterplastic deformation.

Simultaneously as the elongation percentage of the aluminum alloy isimproved as the stacking fault energy is reduced due to thesolidification of oxygen, the twin boundary effectively interrupts slipaction due to a dislocation based on the reduction of the stacking faultenergy, thereby providing a mechanism for improving material strength.Therefore, an aluminum alloy according to the embodiment of the presentinvention exhibits improved workability and improved mechanical strengthsimultaneously due to improved elongation percentage.

FIG. 2 is a graph showing a result of X-ray diffraction analysis formeasuring stacking fault energy (SFE) of an aluminum alloy having a twinboundary or partial dislocation according to an embodiment of thepresent invention. As a method of calculating stacking fault energy, amethod of calculating the stacking fault energy from an X-raydiffraction analysis result was selected to measure stacking faultenergy of the aluminum alloy according to the embodiment of the presentinvention.

Referring to FIG. 2, micro-deformation of about 5% of an as-cast castedaluminum alloy was induced and stacking fault energy (SFE) wascalculated from movements and/or size changes of peaks. The respectiveconstants required in the Equations 1 through 4 below may be calculatedbased on the disclosures and experiment results of the thesis “Theeffect of nitrogen on the stacking fault energy in Fe-15Mn-2Cr-0.6C-xNtwin boundary-induced plasticity steels” (Lee, et al., Vol. 92, pages23-24 of Scripta Materialia, 2014), the thesis “Thermodynamic andphysical properties of FeAl and Fe₃Al: anatomistic study by EAMsimulation” (Ouyang et al., the 2012 edition of Physica B. Vol. 407, pp.4530-4536)), and the thesis “The Relationship between Stacking-faultenergy and x-ray measurements of stacking-fault probability andmicrostrain ((R. P. Reed and R. E. Schramm, the 1974 edition of J. Appl.Phys. Volume 45, page 4705).

$\begin{matrix}{{\Delta \left( {{2\theta_{200}} - {2\theta_{111}}} \right)} = {{- \frac{90\sqrt{3}}{\pi^{2}}}\left( {\frac{\tan \; \theta_{200}}{2} + \frac{\tan \; \theta_{111}}{4}} \right)P_{sf}}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

Here, θ₂₀₀ is the Bragg angle of an aluminum crystal surface 200, θ₁₁₁is the Bragg angle of an aluminum crystal surface 111, and P_(sf) is thestacking fault probability. The θ₂₀₀ may be determined according toEquation 2, and the θ₁₁₁ may be determined according to Equation 3.

2θ₂₀₀=2₂₀₀ ^(cw)−2θ₂₀₀ ^(ANN)  [Equation 2]

Here, θ₂₀₀ ^(cw) is the Bragg angle of the crystal surface 200 of asample in which the 5% deformation is induced, and 2θ₂₀₀ ^(ANN) is theBragg angle of the crystal surface 200 of an annealed sample. 2θ₂₀₀ is ashift value of a relative X-ray peak appearing on the crystal surface200.

2θ₁₁₁=2₁₁₁ ^(cw)−2θ₁₁₁ ^(ANN)  [Equation 3]

Here, θ₁₁₁ ^(cw) the Bragg angle of the crystal surface 111 of thesample in which the 5% strain is induced, and 2θ₁₁₁ ^(ANN) is the Braggangle of the crystal surface 111 of the annealed sample. 2θ₁₁₁ is ashift value of a relative x-ray peak appearing on the crystal surface111.

$\begin{matrix}{{SFE} = {\frac{K_{111}w_{0}G_{(111)}a_{0}A^{- 0.37}}{\pi \sqrt{3}}\frac{< ɛ_{5\; 0}^{2} > 111}{\alpha}}} & \left\lbrack {{Equation}\mspace{14mu} 4} \right\rbrack \\{\alpha = \frac{C_{44} + C_{11} - C_{12}}{3P_{sf}}} & \left\lbrack {{Equation}\mspace{14mu} 5} \right\rbrack\end{matrix}$

In Equation 4, the value of K_(111ω0) is 5.4 (refer to the thesis“Thermodynamic and physical properties of FeAl and Fe₃Al: anatomisticstudy by EAM simulation”), G₍₁₁₁₎ is the shearing stress and is about24.3667 GPa for aluminum, a₀ is the lattice constant and is about0.40495 nm, and A is the vector constant and is 2.8571 for aluminum. ε²₅₀ is the microstrain and the value thereof is determined according tointensity regarding a corresponding surface in an X-ray diffractionanalysis. C₄₄, C₁₁, and C₁₂ in Equation 5 are the elastic constants ofmaterials, where the subscripted numbers indicate respectively givenstress directions.

The stacking fault energy of pure aluminum is about 162 mJ/m². However,in the case of the aluminum alloy according to the embodiment of thepresent invention, the stacking fault energy is reduced by about ⅓. Thestacking fault energy may be appropriately adjusted within a range ofless than 100 mJ/m² depending on types or added amounts of theheterogeneous metal element and the heterogeneous nonmetal element.Specifically, in the aluminum alloy according to an embodiment of thepresent invention, at least one fault from between twin boundary andpartial dislocation appears. The stacking fault energy may beappropriately adjusted within a range of 100 mJ/m² even in the case of aprocessed material and a heat-treated material of an aluminum alloyaccording to an embodiment to the present invention in which oxygen ornitrogen is limitedly solidified as well as the above-stated castedmaterial.

Table 1 shows measured stacking fault energies of aluminum alloys, whichare a casted material, a processed material, and a heat-treatedmaterial, according to an embodiment of the present invention, comparedto the stacking fault energy of pure aluminum. In the A16061 alloy andthe A356 alloy as well as pure aluminum, according to embodiments of thepresent invention, stacking fault energies are remarkably reduced. TheA16061 alloy and the A356 alloy are merely examples, and the presentinvention is not limited thereto. For example, elongation of otheraluminum alloys from AL1xxx series to AL7xxx series, such as AL1050,AL1060, AL1070, AL2011, AL2024, AL3003, AL4032, AL5052, AL5052, AL6063,or AL7075, may be improved through solidification of oxygen or nitrogen.

TABLE 1 Stacking fault energy Material Composition (mJ/m²) Pure Aluminum100% AL 162 Aluminum Casting 100% AL-O 48.65 Material Processed AL6061-O60.55 Aluminum Material Heat-Treated AL6061-O 82.4 Aluminum Material

The reduction of the stacking fault energy facilitates formations of thetwin boundary and the partial dislocation, and thus elongationpercentage may be improved while securing strength.

FIGS. 3A through 3C are stress-deformation graphs showing results ofmeasurement of elongation percentages of aluminum alloys havingdifferent compositions according to an embodiment of the presentinvention.

Referring to FIG. 3A, the elongation percentage of an oxygen-solidifiedaluminum alloy (see the curve As-cast A356-O), which is a castedmaterial according to an embodiment of the present invention, increasedby up to 100% as compared to a casted material (see the curve As-castA356) according to a comparative embodiment. The increase of theelongation percentage is due to reduction of stacking fault energyaccording to an embodiment of the present invention.

Referring to FIG. 3B, the elongation percentage of an oxygen-solidifiedaluminum alloy (see the curve Treated A356-O), which is a heat-treatedmaterial according to an embodiment of the present invention, increasedby up to 100% as compared to a heat-treated aluminum alloy (see thecurve Treated A356) according to a comparative embodiment. Furthermore,the tensile strength (M) of the oxygen-solidified aluminum alloyaccording to an embodiment of the present invention was improved by 30%or more as compared to the heat-treated aluminum alloy according to acomparative embodiment, together with the improvement of the elongationpercentage. The improvement in the tensile strength is due to reductionof stacking fault energy and a twin boundary and/or a partialdislocation associated with the same.

Referring to FIG. 3C, an A356 alloy (see the Curved Treated A356-O),which is another processed material according to an embodiment of thepresent invention, was also oxygen-solidified, and thus tensile strengththereof was improved by 30% and the elongation percentage thereof wasalso increased by 100% or more.

The reduced stacking fault energy may improve the elongation of analuminum alloy, thereby improving the workability of the aluminum alloy.The aluminum alloy is not limited to a casted material, and theelongation percentage may be improved in both of the processed materialand the heat-treated material as described above.

According to another embodiment of the present invention, the aluminumalloy may have a structure in which a precipitated compound is dispersedin an aluminum alloy base. The precipitation compound refers toaluminum, a transition metal, a nonmetal element, and a compound thatmay be formed by including the same. The aluminum-based matrix refers toa matrix formed of pure aluminum or a conventional aluminum alloy. Thealuminum alloy may be fabricated via a casting process described below.

FIG. 4 is a flowchart of a method of fabricating an aluminum alloyaccording to an embodiment of the present invention.

Referring to FIG. 4, according to an embodiment of the presentinvention, melt of an aluminum alloy may be provided (operation S10).The melt may be provided by heating the aluminum alloy using an electricmelting furnace. The heating temperature of the melt may be within arange from 650° C. to 850° C. The heating temperature of the melt ismerely an example, and an appropriate temperature may be determinedaccording to compositions of the aluminum alloy in the melt and/or animpurity in the aluminum alloy. Therefore, the present invention is notlimited thereto.

The aluminum alloy may include any alloying element that may besolidified in aluminum. According to an embodiment, the alloying elementmay include a transition metal. For example, the transition metal may bescandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), vanadium (V),chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu),silver (Ag), zinc (Zn), or at least two or more thereof. According to anembodiment, the transition metal may include at least one of chromium(Cr), iron (Fe), and manganese (Mn), which are Groups VI to VIII elementin period 4. According to another embodiment, in addition to thetransition metal, the alloying element may further include anon-transition metal element, such as silicon (Si), magnesium (Mg),tungsten (W), calcium (Ca), strontium (Sr), and beryllium (Be).Furthermore, the aluminum alloy may be a known alloy including thetransition metal. For example, as a known alloy, an A356 alloy includingFe from 0.2 to 0.3 wt % or an A6061 alloy including Fe from 0.5 to 0.7wt % is available.

In the present specification, a transition metal of a kind actuallyincluded in an aluminum alloy as a starting material provided as a meltfrom among the above-stated transition metals is referred to as a firsttransition metal, whereas a transition metal not included in thealuminum alloy and is of a kind different from the first transitionmetal is referred to as a second transition metal. For example, whenchromium (Cr), iron (Fe), and manganese (Mn), which are transitionmetals, are included as the alloying element in the molten aluminum asthe starting material, chromium (Cr), iron (Fe) and manganese (Mn) thatare included in the molten aluminum in advance may be referred to asfirst transition metals in the present specification. According to anembodiment, powder of a compound of at least one of the first transitionmetals and a nonmetal element is added into the molten aluminumpreliminarily including the first transition metals to form a castedmaterial therefrom and heat treatment is performed thereto, therebyforming a ternary precipitation compound including at least one of thefirst transition metals in an aluminum-based matrix. According toanother embodiment, since the first transition metal is preliminarilyincluded in the molten aluminum, powder of a compound of anon-transition metal and a nonmetal element is added to the moltenaluminum to form a casted material and heat treatment is performedthereto, thereby forming a ternary precipitation compound includingaluminum, a first transition metal, and a nonmetal element in analuminum-based matrix.

According to another embodiment, when the molten aluminum includes onlychromium (Cr) and iron (Fe) and does not include manganese (Mn), thefirst transition metal may include chromium (Cr) and iron (Fe) andmanganese (Mn) not included in the molten aluminum may be referred to asa second transition metal. As described below, powder of a compound ofthe second transition metal and a nonmetal element is added to themolten aluminum to form a casted material and heat treatment isperformed thereto, thereby forming a ternary precipitation compoundincluding at least one of the first transition metal and the secondtransition metal in an aluminum-based matrix.

According to another embodiment, there is no transition metal in themolten aluminum. In this case, powder of a compound of the secondtransition metal and a nonmetal element is added to the aluminum melt toform a casted material and a heat treatment is performed thereto,thereby forming a ternary precipitation compound including the secondtransition metal in an aluminum-based matrix.

A nonmetal element-containing precursor including at least one of oxygen(O), nitrogen (N), and carbon (C) may be added to and mixed in themolten aluminum (operation S20). Next, the added nonmetalelement-containing precursor is decomposed in the molten aluminum, andthus the nonmetal element may be supersaturated in the molten aluminum(S30). The nonmetal element-containing precursor is a compound of afirst reaction compound, which is a compound between the firsttransition metal and the nonmetal element, or a second reactioncompound, which is a compound between the second transition metal (atransition metal different from the first transition metal) and thenonmetal element. According to another embodiment, the nonmetalelement-containing precursor may also be a third reaction compound,which is a compound between a non-transition metal and the nonmetalelement.

According to an embodiment, when zinc (Zn), which is a first transitionmetal, is present as an aluminum alloying element in the moltenaluminum, the first reaction compound may be, for example, a secondtransition metal, e.g., an oxide including chromium (CrO₂), and anonmetal element-containing precursor including the first reactioncompound may be added to the molten aluminum. In another example, thenonmetal element-containing precursor may include a third reactioncompound including a non-transition metal element (e.g., silicon), e.g.,silicon oxide (SiO₂). When the first transition metal already exists inthe molten aluminum, the third reaction compound may be used as thenonmetal element-containing precursor, thereby forming a ternaryprecipitation compound including aluminum, a first transition metal, anda nonmetal element in a casted aluminum-based matrix.

In the case where a transition metal such as zinc, titanium, copper, andiron is not included in the molten aluminum as the alloying element, thenonmetal element-containing precursor is a second reaction compound thatis a compound of a second transition metal and a nonmetal element, wherea nonmetal element-containing precursor including zinc oxide (ZnO),titanium oxide (TiO₂), copper oxide (CuO₂), iron oxide (Fe₂O₃), coppernitride (CuN), iron nitride (FeN), zinc nitride (ZnN), titanium nitrideTiN), magnesium nitride (MgN), or a mixture thereof may be added to themolten aluminum. These are merely examples, and the present invention isnot limited thereto.

According to another embodiment, the nonmetal element-containingprecursor may be a third reaction compound between a non-transitionmetal element and a nonmetal element. For example, the third reactioncompound may include a reaction compound between a non-transitionmetals, such as aluminum (Al), magnesium (Mg), silicon (Si), or tungsten(W), and the non-metal element, that is, aluminum oxide (Al₂O₃),aluminum nitride (AlN), magnesium oxide (MgO₂), silicon oxide (SiO₂),silicon carbide (SiC), silicon nitride (Si₃N₄), tungsten oxide (WO),tungsten nitride (WN), or a mixture thereof. However, they are merelyexamples, and the present invention is not limited thereto. Furthermore,the first through third reaction compounds, which are the nonmetalelement-containing precursors, may be added to the molten aluminum aloneor in combination of two or more thereof.

According to an embodiment, the nonmetal element-containing precursormay be provided in the form of powders, such that the specific surfacearea of the nonmetal element-containing precursor is large and thenonmetal element-containing precursor may be easily decomposed at a hightemperature. For example, the nonmetal element-containing precursor mayhave an average diameter within a range from about 5 nm to about 50 nm.When the diameter is 50 nm or more, the decomposition of the nonmetalelement-containing precursor is difficult, and thus formation of aprecipitation compound described later may be difficult. Theabove-stated first reaction compound and second reaction compound may beadded to the molten aluminum alone or in combination with each other.

According to an embodiment, the nonmetal element-containing precursormay be mixed in the range from 0.01 wt % to 5.0 wt % of the total weightof the molten aluminum. When the mixing amount of the nonmetalelement-containing precursor is less than 0.01 wt %, it is difficult forthe nonmetal element to be supersaturated in the molten aluminum alloy.On the contrary, when the mixing amount exceeds 5.0 wt %, it isdifficult to form a precipitation compound having a uniform compositionincluding three ingredients, that is, aluminum, a transition metal, anda nonmetal element. When an excessive amount of nonmetalelement-containing precursor is present in the molten aluminum,formation of a second phase, such as a reaction compound between thetransition metal and the nonmetal element or a reaction compound betweenaluminum and the non-metal element, may be accelerated. The nonmetalelement may be mixed over the solubility limit, such that the nonmetalelement may be supersaturated with respect to aluminum of analuminum-based matrix at the room temperature within the compositionrange of the nonmetal element-containing precursor.

The molten aluminum in which the nonmetal element is uniformly mixed andsupersaturated is solidified, and thus a casted material is formed(operation S40). The molten aluminum may be solidified by cooling thesame.

Next, the solidified casted material is heat-treated to precipitate aternary reaction compound between aluminum-a transition metal-a nonmetalelement, thereby forming the precipitated compound uniformly dispersedin an aluminum-based matrix (operation S50). The transition metal of theternary reaction compound may include at least one kind of transitionmetal. For example, the ternary reaction compound may be analuminum-zinc-oxygen ternary reaction compound or the ternary reactioncompound may include iron, chromium, scandium, manganese or two or moremetals in place of or in addition to zinc. These compounds are merelyexamples, and the present invention is not limited thereto. The nonmetalelement of the ternary reaction compound may also include at least onenonmetal element. For example, the ternary reaction compound may bealuminum-zinc-oxygen ternary reaction compound or may include nitrogen,carbon, which are nonmetal elements other than oxygen, or all of them inaddition to or in place of oxygen.

As described below with reference to FIG. 4, the precipitation compoundis a nano-sized crystal grain and may have an average size from about 10nm to about 1 μm. When the size of the precipitated compound is lessthan 10 nm, it cannot strongly interact with dislocations formed in analuminum alloy and cannot contribute to the improvement of strength.When the size exceeds 1 μm, the precipitation compound becomes ratherbrittle, and thus it cannot contribute to the improvement of strength.

The precipitation compound, which is a ternary reaction compound, isstably formed in the aluminum-based matrix through heat treatment,rather than being formed in a cooling process for solidification asdescribed later. As a result, according to an embodiment of the presentinvention, the precipitation compound may be uniformly formed in analuminum-based matrix without segregation or coagulation as compared toa non-heated alloy.

The heat treatment may be performed at a temperature within a range fromabout 120° C. to about 600° C. When the temperature is lower than 120°C., precipitation of the reaction compound may not occur. When thetemperature exceeds 600° C., an aluminum-based matrix is melted and,even when the precipitation compound is formed, the precipitationcompound and the aluminum-based matrix are agglomerated with each other,and thus an aluminum alloy structure having the precipitation compounduniformly dispersed therein cannot be obtained.

According to an embodiment, the heat treatment may include a singleheating operation or at least two heating operations. For example, asolidified product may be heat-treated at 540° C. for 12 hours and at160° C. for 8 hours. The above-stated temperature ranges and times aremerely examples and may be appropriately selected to preventagglomeration and segregation of the precipitation compound.

According to an embodiment, the casted material may be further subjectedto plastic working and hardening before the heat treatment (operationS45). The above plastic working may be performed through plasticdeformation, such as rolling, extrusion, drawing, or forging. Theplastic working may be a hot process or a cold process, but the presentinvention is not limited thereto. For example, the plastic working maybe artificially aged without cold working after a solution treatment.The above-stated precipitation compound may be additionally formed inthe aluminum-based matrix through the above-stated plastic working orthe precipitation compound may have a strong interaction with adislocation formed due to a deformation, and thus the strength of analuminum alloy may be further improved.

The below examples relate to specific experimental examples. However,the examples are not intended to limit the invention, but arerepresentative examples for illustrative purposes and, due to commonelectrical, chemical and physical characteristics of transition metals,embodiments other than those shown therein are also included in thepresent invention.

Experimental Example

An aluminum alloy (e.g., A356 alloy) including an aluminum alloy, ironas a first transition metal, and silicon as a non-transition metal wasmelted by using an electric heating furnace to form a melt. Next, zincoxide particles or powder having an average particle size of about 30nm, which is within a range from 5 nm to 50 nm, were added to the meltas a nonmetal element-containing precursor and decomposed. The zincoxide particles were injected and stirred by about 1 wt % or 1.5 wt %,which is in the range from 0.01 wt % to 5.0 wt % of the total wt % ofthe melt. A nonmetal element was supersaturated in the melt of thealuminum alloy and solidified as it is to form a casted material of thealuminum alloy in which oxygen as a nonmetal element is supersaturated.Next, the casted material was subjected to a standard T6 heat treatment.

FIGS. 5A and 5B are transmission electron microscope images showingprecipitation compounds in an aluminum-based matrix by heat treatmentaccording to an embodiment of the present invention, and FIG. 5C is agraph showing ingredients of the precipitation compounds analyzed via anenergy dispersive X-ray spectroscopy (EDS). FIG. 6 is a scanningelectron microscope image showing a cross-sectional microstructure of analuminum alloy casted material supersaturated with a nonmetal elementbefore heat treatment, according to a comparative embodiment.

The aluminum alloy shown in FIGS. 5a and 5b is an aluminum alloy inwhich a precipitation compound was formed after an aluminum alloy castedmaterial to which a ZnO precursor is added by about 1.5 wt % wassubjected to T6 heat treatment for 12 hours at 540° C. and for 8 hoursat 160° C. In order to observe the deformation behavior of the aluminumalloy including the precipitation compound, the aluminum alloy wassubjected to tensile deformation of about 15%, and then observed with atransmission electron microscope. It may be observed that theprecipitation compound (NP) according to an embodiment of the presentinvention strongly interacts with the dislocation (DL).

Referring to FIG. 5C, it may be observed that the precipitation compoundincludes three kinds of elements, aluminum-iron-oxygen. Here, silicon isan ingredient derived from an aluminum alloy existing in the melt and isindependent from the composition of the precipitation compound. Theprecipitation compound is a new reaction compound betweenaluminum-transition metal-nonmetal element which are not precipitatedfrom a conventional aluminum alloy, forms a very favorable interfacewith an aluminum-based matrix, and strongly interacts with a dislocationin the aluminum-based matrix, thereby improving strength of the aluminumalloy.

Referring to FIG. 6, the bright needle-shaped structure is a siliconphase in an aluminum alloy, and the dark region is an aluminum-basedmatrix. Since the aluminum casted material was not subjected to a heattreatment, no observable-sized precipitation compound according to anembodiment of the present invention is observed in the aluminum-basedmatrix.

FIG. 7 is a graph showing results of measuring tensile strength of analuminum alloy according to an embodiment of the present invention andtensile strength of an aluminum alloy according to a comparativeembodiment.

Referring to FIG. 7, an aluminum alloy according to an embodiment of thepresent invention is fabricated by adding a precursor powder of ZnO tothe melt of an A356 alloy to form a casted material and performing aheat treatment to the casted material. The aluminum alloy according tothe comparative embodiment was fabricated by forming a casted materialwithout adding precursor powder to molten aluminum and performing heattreatment thereto under the same conditions. It may be seen that thetensile strength of the aluminum alloy according to the embodiment ofthe present invention (the solid line curve) is improved by about 35% ormore as compared to the aluminum alloy according to the comparativeembodiment (dotted line curve).

FIGS. 8A and 8B are graphs showing increases tensile strength andstrength of aluminum alloys according to various compositions of aprecipitation compound according to an embodiment of the presentinvention, respectively.

For example, referring to FIGS. 8A and 8B, various aluminum alloysincluding precipitation compounds containing transition metals, that is,manganese (curve b), titanium (curve c), and iron (b) in aluminum-basedmatrix including 7 wt % of silicon and 0.3 wt % of magnesium exhibitedimproved strengths as compared to an aluminum alloy including notransition metal (curve a). Particularly, the aluminum alloys includingprecipitation compound containing chromium and iron exhibited improvedstrength, and the aluminum alloy including precipitation compoundcontaining manganese also exhibited improved tensile strength.

FIG. 9 is a graph showing results of measuring tensile strength of analuminum alloy including a precipitation compound according to anotherembodiment and an aluminum alloy according to a comparative embodiment.

Referring to FIG. 9, the aluminum alloy according to an embodiment ofthe present invention is an aluminum alloy including a precipitationcompound formed by adding 1.0 wt % of ZnO precursor powder to the meltof an aluminum alloy of Al—Si (7 wt %)-Mg (0.3 wt %)-Fe (0.3 wt %). Onthe contrary, the aluminum alloy according to the comparative embodimentis an aluminum alloy obtained by forming a casted material withoutadding ZnO, which is a nonmetal element-containing precursor, to themelt of an aluminum alloy and heat-treating the casted material. It wasobserved that the aluminum alloy according to an embodiment of thepresent invention (solid line curve) shows an improvement in yieldstrength of about 22% as compared to the aluminum alloy according to thecomparative embodiment (dotted curve).

FIG. 10 is a graph showing results of measuring tensile strength of analuminum alloy (solid line curve) including a precipitation compoundaccording to another embodiment and an aluminum alloy according to acomparative embodiment.

Referring to FIG. 10, the aluminum alloy according to an embodiment ofthe present invention indicated by the solid line is an aluminum alloyfabricated by forming a casted material by adding about 2.0 wt % of ZnOprecursor powder to the melt of an aluminum alloy of Al—Si (2 wt %)-Mg(1.0 wt %)-Mn (0.3 wt %), re-crystallizing the casted material via 90%plastic rolling, and performing a heat treatment thereto. The aluminumalloy according to the comparative embodiment is an aluminum alloyfabricated by forming a casted material without adding the precursorpowder to the melt of an aluminum alloy, performing the plasticoperation to the casted material, and heat-treating the same. Thealuminum alloy according to an embodiment of the present inventionexhibited yield strength improvement by about 13% as compared to thealuminum alloy according to the comparative embodiment.

As described above, an aluminum alloy including the precipitationcompound between aluminum-transition metal-nonmetal elements accordingto an embodiment of the present invention may be fabricated using acasting operation and a heat treatment operation. The above-describedexperimental examples are merely examples, and the present invention isnot limited thereto. For example, even in the case of nitrogen andcarbon, which are nonmetal elements capable of forming ternary reactioncompounds as stable as a ternary reaction compound formed by usingoxygen, which is a nonmetal element, may form a precipitation compounduniformly din an aluminum-based matrix, thereby improving strength of analuminum alloy.

According to the above embodiments, material properties of an aluminumalloy are enhanced and improved by controlling stacking fault energy oremploying a precipitation compound including a transition metal, whichis obtained via a process employing nanoparticle precursor powder.

According to the embodiment of the present invention, there may beprovided an aluminum alloy with high strength and improved workabilitybased on elongation percentage improved as stacking fault energy isreduced due to solidification of a nonmetal element in an aluminum-basedmatrix and strength improved by a microstructure including a twinboundary or a partial dislocation.

According to another embodiment of the present invention, particles of ametal oxide or a metal nitride are added in the form of powders to themelt of aluminum or an aluminum alloy providing an aluminum matrix toreduce stacking fault energy and/or form a partial dislocation, therebyproviding a highly-stretchable aluminum alloy having the above-describedadvantages in high production yield.

According to another embodiment of the present invention, a compoundincluding aluminum-transition metal-nonmetal element or a compoundincluding the above-stated elements is precipitated in an aluminum-basedmatrix via a heat treatment. As the precipitate is formed uniformly inthe aluminum-based matrix and the precipitation compound stronglyinteracts with a dislocation, an aluminum alloy with significantlyimproved strength may be provided.

According to another embodiment of the present invention, a method ofreliably fabricating an aluminum alloy having the above advantages maybe provided.

While the present disclosure has been described with reference to theembodiments illustrated in the figures, the embodiments are merelyexamples, and it will be understood by those skilled in the art thatvarious changes in form and other embodiments equivalent thereto can beperformed. Therefore, the technical scope of the disclosure is definedby the technical idea of the appended claims.

The drawings and the forgoing description gave examples of the presentinvention. The scope of the present invention, however, is by no meanslimited by these specific examples. Numerous variations, whetherexplicitly given in the specification or not, such as differences instructure, dimension, and use of material, are possible. The scope ofthe invention is at least as broad as given by the following claims.

What is claimed is:
 1. An aluminum alloy comprising: an aluminum-basedmatrix; and a nonmetal element solidified in the aluminum-based matrix,wherein stacking fault energy of the aluminum alloy is decreasedcompared to that of pure aluminum.
 2. The aluminum alloy of claim 1,wherein the nonmetal element comprises at least one of oxygen andnitrogen.
 3. The aluminum alloy of claim 1, wherein the nonmetal elementis solidified to less than or equal to 1 wt % of aluminum of thealuminum-based matrix.
 4. The aluminum alloy of claim 1, wherein thestacking fault energy of the aluminum alloy is less than 100 mJ/m². 5.The aluminum alloy of claim 1, wherein at least a portion of thealuminum-based matrix comprises a twin boundary or a partialdislocation.
 6. The aluminum alloy of claim 1, wherein the nonmetalelement is solidified in the aluminum alloy by adding nanoparticles of ametal compound between the nonmetal element and a heterogeneous metalelement to molten aluminum and decomposing the nanoparticles into thenonmetal element and the heterogeneous metal element.
 7. A method offabricating an aluminum alloy comprising: providing the melt of aluminumor an aluminum alloy providing an aluminum-based matrix; addingnanoparticles of a metal compound between a nonmetal element and aheterogeneous metal element to the melt; uniformly dispersing thenonmetal element and the heterogeneous metal element in the melt throughdecomposition of the nanoparticles into the nonmetal element and theheterogeneous metal element; and cooling the melt so as to solidify thenonmetal element in at least a portion of the aluminum-based matrix. 8.The method of claim 7, wherein the stacking fault energy of the aluminumalloy is less than 100 mJ/m².
 9. The method of claim 7, wherein theheterogeneous metal element comprises copper, iron, zinc, titanium,magnesium, or a mixture of two or more thereof.
 10. The method of claim7, wherein the nonmetal element comprises at least one of oxygen andnitrogen.
 11. The method of claim 7, wherein the nonmetal element issolidified to less than or equal to 1 wt % of aluminum of thealuminum-based matrix.
 12. The method of claim 7, wherein the averagesize of the nanoparticles is from about 20 nm to about 100 nm.
 13. Analuminum alloy comprising: an aluminum-based matrix; and a precipitationcompound dispersed in the aluminum-based matrix, wherein theprecipitation compound comprises a compound containing aluminum, one ormore transition metals, and one or more nonmetal elements or a compoundcontaining the above-stated elements.
 14. The aluminum alloy of claim13, wherein the average size of the precipitation compound is from about10 nm to about 1 μm.
 15. The aluminum alloy of claim 13, wherein thetransition metal comprises at least one of chromium (Cr), iron (Fe), andmanganese (Mn).
 16. The aluminum alloy of claim 13, wherein the nonmetalelement is supersaturated in the aluminum and comprises at least one ofoxygen, nitrogen, and carbon.
 17. The aluminum alloy of claim 13,wherein the precipitation compound is formed via a heat treatment. 18.The aluminum alloy of claim 13, wherein the aluminum-based matrixcomprising: an aluminum alloy; and alloying elements of the aluminumalloy comprises at least one of silicon (Si), zinc (Zn), magnesium (Mg),and copper (Cu).
 19. A method of fabricating an aluminum alloycomprising: providing the melt of an aluminum alloy comprising aluminumand a first transition metal; adding a nonmetal element-containingprecursor comprising at least one of a first reaction compound betweenthe first transition metal and a nonmetal element, a second reactioncompound between a second transition metal different from the firsttransition metal and the nonmetal element, and a third reaction compoundbetween a non-transition metal and the nonmetal element to the melt;supersaturating the nonmetal element in the melt through decompositionof the nonmetal element-containing precursor in the melt; forming acasted material by hardening the melt; and forming a precipitationcompound between aluminum, a transition metal, and a nonmetal elementdispersed in an aluminum-based matrix by heat-treating the hardenedcasted material.
 20. The method of claim 19, wherein the firsttransition metal comprises at least one of chromium (Cr), iron (Fe), andmanganese (Mn).
 21. The method of claim 19, wherein the nonmetal elementcomprises at least one of oxygen, nitrogen, and carbon.
 22. The methodof claim 19, wherein the non-transition metal of the third reactioncompound comprises at least one of aluminum (Al), silicon (Si),magnesium (Mg), and tungsten (W).
 23. The method of claim 19, whereinthe nonmetal element-containing precursor is added to the melt in theform of power having the average diameter within a range from about 5 nmto about 50 nm.
 24. The method of claim 23, wherein the nonmetalelement-containing precursor is added in the range from 0.01 wt % to 5.0wt % of the total weight of the melt.
 25. The method of claim 19,further comprising plastic working and hardening the hardened castedmaterial before the hardened casted material is heat treated.
 26. Themethod of claim 19, wherein the heat treatment is performed at atemperature within a range from 120° C. to 600° C.